Machine for stacking and accumulating stacks of collapsed cartons



Dec. 19, 1961 w. WILSON ET AL MACHINE FOR S TACKING AND ACCUMULATING STACKS OF COLLAPSED CARTONS Original Filed April 29, 1957 4 Sheets-Sheet l Dec. 19, 1961 H. W. WILSON ET AL MACHINE FOR STACKING AND ACCUMULATING STACKS OF COLLAPSED CARTONS Original Filed April 29, 1957 4 Sheets-Sheet 2 iNVENTORS mm) w w/um Dec. 19, 1961 H. w. WILSON ETAL MACHINE FOR STACKING AND ACCUMULATING. STACKS OF COLLAPSED CARTONS Original Filed April 29, 1957 4 Sheets-Sheet 3 nus NN\ @N QQ 5 Q wk INVENTORS A A/RAY V14 W/[SON- ail/N70 L. Dal/(V551 .AUJWKZIEY Dec. 19, 1961 H. w. WILSON ETAL MACHINE FOR STACKING AND ACCUMULATING STACKS OF COLLAPSED CARTONS Original Filed April 29, 1957 4 Sheets-Sheet 4 IE n? vm 5 VF M Ta, m Q

i oww 3 3 Unite Sates Patent MACHINE FOR STACKING AND ACCUMULATING This invention relates to apparatus for packaging collapsed cartons. More particularly, the invention relates to apparatus for stacking and accumulating stacks of collapsed cartons. This application is a division of application Serial No. 655,774, filed April 29, 1957, now Patent No. 2,947,125

Corrugated paper boxes and cartons are commonly shipped from the manufacturers to the users in the collapsed form known in industry terminology as k.d.f., meaning knocked-doWn-flat. At this k.d.f. stage, the carton blanks have been properly slotted, scored and folded, and the two end panels have been glued or otherwise connected by methods that are conventional in the industry, so that all the user has to do is to open the k.d.f. carton out and fold over the bottom and top flaps.

However, the shipping of k.d.f. cartons has presented a hitherto unsolved packaging problem to which the present invention is directed. The method most general in the prior art has been to tie wire or twine around a small stack of about 25 cartons, forming a tied bundle. The bundles have then either been packed entirely by hand, which is costly, or a number of bundles have been stacked by hand on wooden pallets of the so-called returnable type, for handling by fork-lift trucks. Returnable pallets, however, are expensive to use, not only because of the material cost but also because of the necessity for recording their whereabouts, constantly maintaining them in proper condition, and returning them to the shipper. The shipper must maintain a considerable investment in pallets if he is to have enough on hand for each shipment, because, at any one time, many pallets are at the customers warehouses or are in trucks en route to the customers. .Also, pallets are often lost or broken in shipment. Heretofore, non-returnable pallets have been still more expensive in the long run and have not been used to any great extent.

Another problem has been that standard pallets usually do not conform to the dimensions of the bundled cartons; so when the cartons were stacked on the pallets they either failed to fill the surface of the pallet or over hung the edges. In either event, space was wasted and it was not possible when using standard pallets to put the maximum number of cartons into the shipping spaces available in rail cars or trucks. Moreover, a great variety of box sizes are used, each size remaining different when the boxes are knocked down flat, so that it was only coincidence when the pallet size and the box size coincided. For the same reason, much space is lost in warehouses when storing boxes on pallets.

The inconvenience of these prior-art packaging methods has been overcome by an invention by Harry W. Wilson, described in his application Serial No. 592,185, filed June 18, 1956, now abandoned for a self-palletized package and in his continuation-in-part application, Serial No. 651,615, filed April 9, 1957. In that invention the bale is formed by strapping together a sufiicient number of cartons to make, when compressed and secured together, a bundle or bale one-half the width of a truck or rail car. The finished self-palletized bale is characterized by resting on a pair of runners that formed an integral part of the package, being held to the package Patented Dec. 19, 1961 ICC Also, the self-palletized bale is characterized by the fact that the cartons stand on edge and are held under pressure during strapping so that all the air is squeezed out and the surfaces made equiplanar. All this is explained in the applications referred to. The self-palletized bale is very stable and can support additional layers of unpalletized bales, for handling several layers as a unit, and the units can be stacked on top of each other in warehouses. A relatively inexpensive, unitary, and highly efficient package results. The pallet and bale are the same size; so the problems in warehousing, storage and transportation are solved. The low cost of materials makes unnecessary the return of pallets and eliminates the bookkeeping that goes with returnable pallets.

This new bale has another extraordinary feature: it makes it possible to provide self-palletized bales even from cartons that are too small to be handled in a single stack by fork-lift trucks, ie where there is not enough room to provide entry space for the forks, which are usually about 28" to 32" apart. This important result is accomplished by a novel double stack of the smaller cartons, joined only by locking sheets (or cap sheets, as they are sometimes called) that are strapped into the bale. By pitting against each other, through the locking sheets, those forces that tend to cause the bale to come apart, the bale can be held together by flanged locking sheets of corrugated paper. The high shear or tensile strength of sheet material when subjected to stretching, is availed of in a novel manner fully explained in the above-identified continuation-impart application.

In any event, when this improved bale was first intro duced, the stacking had to be done by hand and the entire operation had to be done on a batch-basis, usually by two men. It involved a lot of hard work and manual labor. It was difficult for hand labor in the packaging stage to keep up with modern carton production machines, which can produce a hundred thousand k.d.f. cartons in an eight-hour day.

One object of the present invention is tosolve this packaging problem by providing a method and apparatus which greatly simplify the packaging of k.d.f.,boxes into self-palletized bales, or other convenient types of packages.

Another object of the invention is to provide a rapid package-production machine employing a novel method, which automatically forms large stacks'from-small ones.

Another object is to provide apparatus that automatically advances the large stacks after a certain number of small stacks has been incorporated into it. I

Another object is to enable the rapid and economical formation of large stacks of k.d.f. cartons into secured packages, with or without a self-palletizing construction.

Other objects and advantages of the invention will appear from the following description of a preferred em-' bodiment.

In the drawings:

FIG. 1 is a view in side elevation of a machine embody ing the principles of the invention, with a partly stacked package in the stacker, and two stacked packages in the accumulator, the outer end of the conveyor into the machine being cut off, and some parts being broken away to show other parts.

FIG. 2 is a view in elevation of the stop gate at the entry to the stacker, shown in its open, depressed, position, in comparison with the closed, raised, position shown in FIG. 1.

FIG. 3 is a view in vertical section taken along the line 3-3 in FIG. 1 and showing the stacking portion of the device, with a partially completed stack therein and with some parts of the machine cut away.

FIG. 4 is a view in vertical section on an enlarged scale,

taken along the line 4-4 in FIG. 1 and also showing a portion of the stacking device, but with the stack elevator raising a small stack through the horizontal gates, which are therefore shown in their open position instead of the closed position shown in FIG. 1, where the stack elevator is in its lowered position.

FIG. 5 is a top plan View in horizontal section on the same scale as in FIG. 4, taken along the line 55 in FIG. 1, also showing the stacking device, but with the ejector advanced about two-thirds of the way toward the end of its ejecting stroke to advance a completed stack into the accumulator. The vertical gates at the left end of the stacker are shown in solid lines in their open position, where they are pushed by the stack of cartons being ejected, and broken lines indicate the normal, closed position of these gates.

FIG. 6 is a view in side elevation of the ejector, taken along the line 66 in FIG. 3 and showing the control switches thereon and the switch operating cam.

FIG. 7 is a view in vertical section taken along the line 7-7 in FIG. 1, with some parts cut away to show the device with greater clarity. In particular, FIG. 7 shows the accumulator station with stacks of k.d.f. cartons therein and a lower cap or locking sheet inserted between the bottom of the stack and the conveyor belts, the lower conveyor belts being shown in their lower, retracted position.

FIG. 8 is an electrical circuit diagram of the device.

GENERAL DESCRIPTION OF THE METHOD AND DEVICE (FIG. I)

The machine shown in the drawings is part of a multistage device, each stage being adapted to perform one or more steps in the method of this invention and being related to the other stages. In general, small stacks A of k.d.f. cartons B are placed on an introductory conveyor C, which leads into a stacking device D, where the small stacks A, usually about 25 k.d.f. cartons B each, are made into large stacks E many times as big, such as stacks of about 175 to 200 cartons. The large stack E is then advanced by an ejector F into the next stage of operation, which may be called an accumulator G.

In the accumulator G a first large stack E is held until a second similar stack E arrives. In those bales that are to be self-palletized, a single oversize bottom cap or locking sheet H may then be applied beneath the two stacks, E and E For most operations, it is advisable to add the cap sheet manually, though it may be added by automatic machinery.

When the operator has the bottom cap sheet H in place (if one is used) and at the proper time to advance the two stacks E, and E he presses a button that send them out of the accumulator G while folding up the protruding sides of the cap sheet H to provide a pair of stabilizing flanges whose importance is explained in the referred-to applications. Subsequent operations take place as explained in the parent application.

The operating sequence and detailed operation of the machine will be described after the following description of each stage or section thereof.

INTRODUCTORY CONVEYOR C (FIG. 1)

The k.d.f. cartons B to be packed are preferably conveyed to the unit in a continuous series of small stacks A of a predetermined quantity. For example, there may be 25 cartons B in each stack A, or there may be more or fewer cartons in each stack A, the quantity being varied to suit the need. The stacks A reach the machine on the introductory conveyor C, which may comprise a frame 20, supporting a number of freely mounted rollers 21 at heights graduated to produce a gravity feed, the lowest roller 21 being at the intake end of the machine. Such conveyors C are well known in the art and need not be further illustrated; the gravity feed is preferred because some of the stacks are stopped before entering the stacker D, but other types of feed may be used.

4 THE STOP GATE 22 (FIGS. 1 AND 2 At the end of the introductory conveyor C, just beyond the last and lowest roller 21, is an electrically operated stop gate 22 controlling the entry of the stacks A so that only one stack A at a time can enter the stacker D. The stop gate 22 (see FIG. 2) may comprise a vertical flange or strip 23 mounted at the outer end of an arm or strip 24. The arm 24 may be pivotally mounted near its inner end on a pivot 25, journaled on the frame 35. A crank arm 26 depends from the inner end of the arm 24, on the opposite side of the pivot 25 from the flange 23, and one end of a tension spring 27 is anchored to the crank 26. The other end of the spring 27 is secured to the frame 20, and so pulls the crank arm 26 toward the frame 20, thereby urging the stop gate 22 up to a normal elevated or stopping position, where carton stacks A will engage the flange 23 and be stopped from entering the stacker D.

A normally de-energized solenoid 28 may be mounted on the frame 35 outboard from the pivot 25, with its core pivotally secured to the arm 24 and thereby adapted upon energization of the solenoid 28 to pull down the arm 24 and open the stop gate 22 so that a stack A can pass through. Upon later de-energization by a switch 42 of the solenoid 28 the spring 27 pulls the stop gate 22 up again to where it will block the passage of the next carton stack A. The electric circuit that controls the stop gate 22 will be explained in connection with the stacking device D.

FEEDING THE STACKS A INTO THE sTAcKER D (FIGS. 1 AND 34 From the stop gate 22, a small stack A is carried by a spaced-apart parallel pair of feed belts 30 and 31 into the stacker D. The belts 30 and 31 are continuous and are preferably mounted on respective drive rollers 32, secured to a common drive shaft 33, and idling rollers 34, on another shaft which may also be driven if desired. The shafts are preferably jonrnaled in or otherwise rotatably supported by a main stacker frame 35 which may, if desired, be a portion of an overall main frame, or may be separate. The drive shaft 33 may be driven by a motor 36 through a chain 37.

The belts 30 and 31 convey each stack or bundle A from the stop gate 22, between two pairs of straightening guides 38 and, if desired, between two straightening rollers 38a, which are preferably driven, as by belt 3811 at the same speed as the belts 30 and 31. In any event, it is important to form straight stacks. The belts 30, 31 convey the straightened stack A into the stacker D, where the bundle A is stopped by a pair of vertically extending rigid stop members 39 directly below a pair of vertically extending gates 40 and 41. The momentum of the cartons B as they strike the stop members 39 there may also be and preferably is a center stop member, extending up from the bottom but obscured by the cartons in the drawings) serves to straighten the front and rear ends of the stack A, just as the guides 38 and 38a serve to straighten the sides.

Before reaching the stops 39 and soon after leaving the stop gate 22, the bundle A passed over and opened a gate release switch 42, which de-actuated a holding relay 43 (see FIG. 13) that had been energizing the solenoid 28 to hold the stop gate 22 open. The solenoid 28 being de-energized, the spring 27 pulls the stop gate 22 up to prevent a second stack A from passing. Preferably, the switch 42 is located less than the length of a carton B from the stop gate 22, so that the stop gate 22 can separate an immediately adjacent stack A from the first stack A. Separation is possible, it may be added, because the feed belts 30, 31 are moving the first stack A faster than the succeeding stack A is being moved by gravity over the rollers 21, resulting in a gap between the stacks into which the flange 23 can move.

THE STACKER FRAME AND GATES (FIGS. 1

AND 3-5) The vertical gates 40, 41 whose lower ends lie above the upper ends of the stops 39, are pivoted on hinges 44 to rmpective vertical frame members 45 of the stacker frame 35, and the gates 40, 41 are normally urged to their carton-stopping position transverse to the belts 30, 31 by strong springs 46.

The stacker D also has rear vertical frame members 47 that extend parallel to the edges of the belts 30, 31 and whose upper portions are provided with transversely extending portions 48. Thus the gates 40, 41 (with the stops 3-9) and frame members 45, 47 and 48 enclose and define the corners of a rectangular right prism, within which the boxes are stacked and by which they are kept aligned. There are no lower portions of the members 48, because if there were they would prevent entry of the cartons B into the stacker D.

A pair of normally horizontal gates 50 51 are pivotally mounted on horizontal rods 52 level with the lower ends of the gates 40, 41 and the transverse frame members 48. The rods 52 are supported rotatably by brackets 53 on the frame members 45 and 47, so that they can swing upwardly and outwardly as the stack A is raised in the manner described in the next section. Return springs 54 are secured between arms 55 on the horizontal gates 50, 51 and books 56 on the frames 45, to urge the gates 50, 51 to their normal position, while permitting them to lift and swing out to admit cartons from below. The outer ends 55:: of the arms 55 serve as stops to prevent the gates 50, 51 from falling below their horizontal position.

The frames 47 may be made adjustable relative to each other and to the frame members 45 for accommodating different lengths and widths of k.d.f. cartons B, where that is desirable. Some of the adjustment features have been omitted from some of the drawings, where they would serve the cause of confusion more than the cause of clarity; after all, the man skilled in the art knows well how to provide such adjustability. Threaded rods 57, rails 58, and frame carriages 59 sufiice to show the widthwise adjustability of the frame members, the upper and lower rods preferably being joined by chains 59a and rotated together by a handwheel 59b. Lengthwise adjustmen-t is obtained by the carriage 59 and rails 59c.

THE STACKER D AND ITS STACKIN G ELEVATOR 60 (FIGS. 1, 3 AND 4) Directly below the area enclosed by the stacker frame is a stacking elevator 60,.comprising a cylinder 61, a piston 62, and a platform 63 supported on the upper end of the piston 62. Upward movement of the piston 62 therefore causes the elevator 60 to lift a stack A off the belts 30, 3'1 and move them upwardly.

Mounted on one stop 39 is electrical switch 64, which is normally open, so far as the elevator 60 is concerned, and is closed upon engagement of the stack A. Closure of the switch 64 actuates a holding relay 65 (FIG. 8) and energizes a solenoid valve 66a, (causing fluid to enter the bottom of the stacker cylinder 61, which is preferably pneumatic but may be hydraulic. The fluid then causes the piston 62 to move upwardly. 'Ihe generally rectangular platform 63 is positioned between the belts 30 and 31 and in the area bounded by the frame members 45 and 47; so as the piston 62 rises, the stacking platform 63 engages the bottom of the stack A and lifts it up off the belts 30 and 31 and above the stops 39, and pushes it through the normally horizontal gates 50, 51 which swing upwardly and outwardly to permit the stack A to pass through. If some stacks A were previously supported on the gates 50, 51 they, too, are carried up by the elevator 60 until the lower end 67 of the stack has passed beyond the inner edges of the gates 50, 5-1, at which time the return springs 54 close the gates 50, 51 downwardly and inwardly to their normal horizontal position.

Closure of the switch 64 also opens a circuit to the belt-driving motor 36, but the motor circuit closes as soon as the stack A rises above the switch 64. Since this takes only a few seconds, the slowing or stopping of the belts 30, 31 is hardly noticeable unless the stacker elevator 60 fails to lift the stack A above the switch 64. 'In that event, the switch 64 serves a safety function by preventing the jamming which would occur if the belts 3t), 31 could then move additional cartons into the stacker D.

When the gates 50, 51 drop back to a horizontal position, one of them (e.g. 50 in FIG. 4) may actuate an electrical switch 68 which releases the holding relay '65 and thereby tie-energizes the solenoid 66. Or the elevator 60 may actuate the switch 68 at the upper end of its stroke. As a result of this actuation, however achieved, the supply of fluid to the lower end of the stacking cylinder 61 is cut off, and its porting is reversed so that fluid enters the upper end of the cylinder 61 and lowers the elevator 60 to a level below the belts 30, 3 1. The gates 50, 51 intercept the stack A and support its lower end 67 as the elevator 60 moves down away from it. The cartons B, at this point, are held in alignment not only by the forward vertical gates 40, 41 and frames 45 but also by the frame members 47 and 48.

The elevator 60 is steadied by a pair of guide sleeves 70 that encircle vertical rod-like stationary guides 71. Each time the piston 62 rises, the guide sleeves 70 rise in relation to the stationary guide rods 71. Attached to one guide sleeve 76 is a bracket 72. When the bracket 72 rises, it releases the pressure on a spring 73, allowing it to extend. The lower end of the spring 73 rests on a stationary, frame-supported member '74, while the upper end of the spring 73 is secured to a reciprocating shaft 75 that extends down through an opening through the member 74. A dog 76 pivoted at 77 to the lower end of the shaft 75 rides up and down; on its upstroke its'free pivoted attachment to the shaft 75 causes it to slide on by a tooth 78 of a ratchet wheel 79. However, when the piston 62 moves down and the spring 73 is compressed, the dog 76 moves down and engages the ratchet tooth 78 and moves it down, or forward, one step.

In this manner, each time the piston 62 returns to its lower position, the ratchet 79 is moved forward one step. One particular step, which (for example) may be the seventh step of a seven-toothed ratchet wheel 7 9, is provided with an extension member 89 adjacent it, and this extension member 80 adapted to engage and close the contact of a normally open micro-switch 81, whose function will be explained in the next section. In other words, the switch 81 is closed only on the lowering of the piston 62 and platforms- 63 for the seventh time. Of course, the ratchet wheel 79 may have more or fewer teeth, and may be energized on a different step, if that is desirable.

The ratchet 79 thus acts as a counter and so may be replaced by another suitable type of cycle-counting de vice, but some form of counter is required for the operation about to be described. Each time the elevator 60 rises, another stack A is added to the bottom of a larger stack located above the horizontal gates 50, 51, and the large stack E is gradually built up. After a tot'ahof seven stacks A (in this example) have been accumulated into the one stack E, the next stage is to move the completed stack E out of the stacker D into the accumulator G.

Before passing to the next section, it should also be noted that each time the piston 62 is lowered the bracket 72 also closes a switch 82 which energizes the relay 43 and, through it, the solenoid 28, thereby pulling the stop gate 22 down so that another bundle A can pass on to the stacker D. However, on the seventh stroke down, the counter 79 indirectly (in a manner to be explained in the next section) opens a switch 83 that stops the motor 36.

7 Then the belts 30, 31 stop, so that even though the stop gate 22 is open, no stack A will be moved into the stacker D during movement of the ejector F.

Also, it may be noted here that the normally horizontal stacker gate 51 on the side of the frame opposite the switch 68 is provided with an interlock switch 69 which prevents forward movement of the ejector F in case the gate 51 is not closed. On the previous six strokes, failure of the gate 51 to close would make little, if any, difference, because stacking would continue unaffected, but it would cause trouble if the ejector F were to attempt to move a tilted stack E into the accumulator G. If the switch 68 is arranged for actuation by the elevator 60, then there are two interlock switches 69, one for each gate 50, 51.

ADVANCING THE STACK E FROM THE STACKER D TO THE ACCUMULATOR G: THE EJECTOR F (FIGS. 1, 3. AND 6) Closing the counter-actuated switch 81 actuates a holding relay 84, which in turn energizes a solenoid 85. A solenoid-controlled valve 85a then sends fluid to the right hand port 86 (FIG. 1) of a pneumatic cylinder 87 which is mounted rigidly to a stationary cross member 88 of the frame 35. The cylinder 87 is part of the ejector F, and entry of air into the port 86 causes a piston 89 to move horizontally from right to left, as shown in FIGS. 1 and 5 (or from left to right as seen in FIG. 6). The piston 89 supports a vertically disposed ejector pusher block 90 on its outer end. The pusher 90 is of substantial vertical extent, and engages the entire height of the large stack E.

Therefore, as the cylinder 87 fills with air and the piston 39 and pusher 90 move forward, the stack E is forced forward with considerable pressure against the springmounted vertical gates 40, 41. The springs 46 yield to the pressure of the ejecting ram F, as transmitted through the stack E. and the gates 41, 40 open outwardly (to the left in FIG. 5) permitting the stack E to be pushed through.

The ejector F is aided by two pairs of conveyor belts, lower belts 91 and upper belts 92, which at this time are freely moved by the stack E around their lower pairs of rollers 93 and 94 and upper rollers 95 and 96, respectively, enabling the ejector F to push against relatively low forces of friction. The upper belts 92 also restrain the upper end of the stack E and keep it from expanding due to internal pressures; e.g., in case some of the k.d.f. cartons B are warped. Chains 97 connecting the respective drive shafts of the belts 91 and 92 move them at the same speed; so the belts 91 and 92 also serve to convey the top of the stack E at the same speed as the bottom, as they move the stack E into the accumulator G. It will also be noted that the upper belts 92 actually extend over and overlie the stacker D and serve there to hold down the top of the stack E and aid from the beginning the movement of the stack E by the ejector F. Moreover, the height of the upper belts 92 is adjustable by threaded rods 98 and carriages 99 that support the rollers and shafts of the upper belts 92.

As FIG. 6 shows, a switch-operating earn 100 moves with the pusher 90, being attached to the end of a cam rod 101 that slides over a guide 102. When the cam 100 is in its extreme right hand position (as in FIGS. 1 and 13) it holds the switch 83 closed; therefore, when it begins to move, the cam 100 opens the switch 83, and this opens the circuit to the motor 36, stopping the belts 30 and 31. This prevents jamming of the stacker D during operation of the ejector F. The belts 30, 31 remain stationary until the cam 100 returns to close the switch 83 at the end of the ejector stroke.

When the stack E passes beyond the gates 40, 41, the springs 46 close them. Shortly thereafter, the cam 100 engages and opens a normally closed switch 103, deenergizing the relay 84 and the solenoid valve 85 and energizing (by a relay-controlled switch 341 through a switch 104 which was closed upon the opening of the switch 83) another solenoid 105. The valve 105a then sends air into the left hand port 106 (as in FIG. 1) of the cylinder 87, while the right hand side of the cylinder 87 is bled. The piston 89 is thereby returned to the right, retracting the pusher and leaving a stack E between the belts 91, 92 in the accumulator G. This first stack E of cartons then remains stationary while the stacker D begins another cycle.

When the ejector F returns to its original (all the way to the right in FIG. 1) position, the cam opens the switch 104, de-energizing the solenoid 105. At the same time, the cam 100 closes the switch 83, starting the motor 36. The belts 30 and 31 then move again and carry a new small stack A into the stacker D. Once again, a series of stacks A (for example, seven of them) are lifted sequentially by the stacking elevator 60 above the gates 50, 51 to form a second large stack E When that stack E has been completed and the seventh ratchet tooth has been turned, energizing the switch 81 and the relay 84, the ejector F again moves forward, pushing the stack E in front of it, past the vertical gates 40, 41 and into contact with the first single-pack E This time the action is somewhat different. The second-pack E is pushed against the first-pack E and engages it and begins pushing it forward, the ejector F pushing both packs E and E along and between the belts 91 and 92. Soon after commencing to move, the stack E engages and closes a normally open switch 107, preferably located between the lower belts 91. The switch 107 bypasses the switch 103 that would normally stop the piston 89 at the position to which it pushed forward the stack E As a result, the piston 89 continues to move the stacks E and E forward, unaffected by the switch 103, and moves them an additional distance until the cam 100 opens another normally closed switch 108 whose closure finally does deenergize the relay 84 and return the ejector F to its original position, as before.

One purpose of this double stroking of the ejector F is so that the two single packs E and E will be in their correct position for the next operation. Yet it would waste energy to push the stack E the first time as far as the stack E finally gets pushed; so the short first stroke saves time and energy. Another purpose of the double stroking of the ejector D is to insure contact between the two stacks E and B In the first stroke, the stack E is pushed only far enough to allow the gates 40 and 41 to close. Then when the stack E is ejected it comes into contact with the stack E before it reaches the belts 91, the end point of these belts being positioned as shown for that purpose. If the first stack E were stroked further on its ejection so that the second stack E reached the belts 91 before touching the first stack E the belts 91 would begin moving, carrying the stack E with them and there would be a gap between the two stacks E and E It is very important that there be no such gap in the accumulator G, because that is where the lower locking sheet is applied that holds the stacks E and E together. There would be no feasible way of curing such a gap, and the resultant bale would be faulty.

The locations of the electric contacts 107, 108 are adjustable for different sizes of cartons, and it may be mentioned here, again, that the frame of the accumulator G. like that of the stacker D, may be adjustable as shown, by the threaded rods 57, rails 58, and carriages 59, etc., to receive different sizes of cartons. It is obvious to the man in the art how this may be done, so the adjustability has not been described in detail.

THE ACCUMULATOR G (FIGS. 1 AND 6) The lower belts 91 are supported by rollers 93 and 94 that are journaled in a movable frame 110 that can be lowered to retract the belts 91 downward, leaving the stacks E and E supported by their edges on a pair of parallel horizontal flanges, wings or support members 111. The purpose of lowering the belts 91 is to permit insertion of the lower cap or locking sheet H beneath the packs E and E and the wings 111 and above the belts 91. Then, when the frame 119 and belts 91 are raised again, the belts 91 will support both the locking sheet H and the stacks E and E Although the wings 111 are then be tween the edges of the packs E and E and the locking sheet II, this does not interfere with the forward movement of the stacks E and E and the locking sheet H as a unit, since the Wings 111 are only at the edges, and once the stacks have been moved forward out of the accumulator D the locking sheet H is fully united with them.

The horizontal wings 111 may be supported (at adjustable widths and lengths) from the top of the frame 35 by rods 112, while the belt-supporting frame 110 may be supported by links 113- pivoted at one end 114 to the frame 110 and at the other end 115 to the frame 35, so that the frame 118 can be raised and loweredrelative to the frame 35 by a cylinder 116 (pivotally secured to the frame 35) and piston 117 (pivotally secured to the'frame 110). The links 11?: give a parallelogram type of movement. The raising and lowering of the piston 117, frame 110, and belts 91 may be controlled by a solenoid valve 118a for the cylinder 116, the solenoid 118 being deenergized by a relay 119 on the opening of a normally closed switch 120. The switch 128 is opened automatically when the stack E reaches the forwardmost position to which it is pushed by the ejector F, for the stack E then engages and rests upon the switch 120, causing the belts 91 to be lowered at once, until the frame 110- rests on the rests 121 and the single-packs E and E are suspended on the wings 111, so that the locking sheet H may then be inserted. The locking sheet H may not be, and usually is not, applied on some occasions, as will be explained later, and other devices may be used instead, if desired. When employed, the locking sheet H is preferably approximately 4"6 wider on each side than the packs E and E for a purpose which will appear soon, and it is usually slipped in manually and centered by eye, though automatic insertion and centering are possible.

The belts 91 and 92" are free moving in the direction of flow, right to left, in FIG. 1, due to the presence of a cam clutch arrangement 122, placed between a driving motor 123 and a drive gear 124. The cam clutch 122 allows the belts 91, 92 to be pushed forward by freewheeling, without driving the motor 123; however, when the motor 123 is actuated, the cam clutch 122 locks and drives the belts 91 and 92 to move the stacks E and E from right to left, as in FIG. 1.

If the press is clear (as explained in the parent application) and after the lower locking sheet H is in place, (or if no locking sheet is to be used, whenever the operator so desires), a manual switch 125 may be closed (see FIG. 8). This switch 125, through the relay 119, energizes the solenoid 1.18 to pressurize the cylinder 116 and move the piston 117 and the frame '110 upwardly, placing the belts 91 in contact with the cap sheet Hand lifting the stacks E and E off the Wings 111.

Then the operator can press a manual switch 126 that energizes a relay 127, which in turn actuates the motor 123. (The switches 125 and 126 may be actuated simultaneously by a single switch button.) A normally open interlock switch 128 keeps the relay 127 from actuating the motor 123 if the belts 91 are not in their lifted position, the switch 128 being closed when the frame 110 is in its raised position. Also the interlock switch 128 keeps the ejector F from acting even though it has received a signal from switch 81 unless the belts 91 are raised. The signal from the switch -81 is held in the machine until the belts 91 are again in the raised position. When the motor 123 is actuated, the clutch 122 is engaged to drive the belts 91 and 92, and the belts move the packs E and E, with the locking sheet H from right to left as in FIG. 1. While moving, the projecting edges 130 of the locking sheet H come in contact with curved metal rigid folding guides 131one of which is on each side of the When the stacks E and E move out of the accumulator G, the spring-urged switch is restored to its normally closed position, holding the belts 91, 92 in their raised position until the switch 120 is again reopened.

THE ELECTRIC CIRCUIT (FIG. 8)

Most of the operating elements of the circuit have already been discussed in preceding sections, but it remains to trace the preferred circuitry. Preferably, the power is supplied by a source 260 of 220-volt 3-phase current, which is connected to the motors 36 and 123 by leads 262, 263 and 264. All the connections between these leads and the motors, however, are made through normally open relays 265 and 266, and these relays are actuated by a master-control circuit whose description will form the body of this section.

The circuit is provided with a master-control relay 27 which is energized upon closure of a master-control switch 271 and which obtains its power by tapping across leads 263 and 264, via leads 273 and 274. Unless the mastercontrol switch 271 is closed, the master-control relay 270 is open and nothing in the circuit will operate. All the remaining circuits are in series with the main relay 270. Most of them are in parallel with each other across main power lines 275 and 276, but direct control over the motors 36 and 123 is maintained by leads 277 and 278 which are also in series with the master-control relay 270.

(A) The circuit controlling the stop gate 22 The relay 43 that controls the stop gate 22 may be in a circuit including a lead 286 connected between the main power line 276 and the gate-release switch 42. The gate-release switch 42 is connected by a lead 281, to a relay-controlled switch 282. In its normal, non-operative position, the switch 282 is connected by a lead 283 to the normally open switch 82. A manual starting switch 284 is also preferably connected to the lead 283 in parallel with the switch 82. The opposite sides of the normally open switches 82 and 284 are connected by a lead 285 to one side of the relay 43. A lead 286 joins the lead 285 to a normally open contact 287, which is closed by the switch 282 upon energization of the relay 43. A lead 288 joins the leads 285 and 286 to one side of the solenoid 28 which, when energized, pulls stop gate 22 down. A lead 289 from the opposite side of the solenoid 28, and a lead 290 from the opposite side of the relay 43, are connected together to a lead 291 which is connected through a lead 292 to the other power line 275.

Thus, when the switch '82 is in the position shown, which is the one normally assumed, no current can pass because the switch 282 is simply connected in series to a pair of open switches 82 and 284. Therefore, the relay 43 and the solenoid 28 are not normally energized.

It will be recalled that the seating of the elevator 60 at the lower end of its stroke closes the switch 82. Then, current will pass from the power line 276 through the lead 288, the switch 42, the lead 281, the switch 282, the lead 283, the switch 82 and the lead 285 into the relay 43 and out therefrom via the leads 290, 291 and 292 to the power line 275, energizing the relay 43. At the same time, current from the lead 285 passes via lead 288 to the solenoid 28 and from it, via lead 289, to the lead 291, so that the solenoid 28 is also energized directly upon closure of the switch 82. However, this is only its initial energization. The relay 43, being energized, moves the switch 282 away from the lead 283 to the contact 287. From then on, the switches 82 and 283 are out of the circuit, and current then passes from the power line 276 via lead 280, switch 42, lead 281, switch 282,

contact 287 and leads 286 and 285 into the relay 43.

11 to hold it energized and thereby keep the switch 282 against the contact 287. At the same time, of course, power passes from the contact 287 via leads 286 and 288 to the solenoid 28 and from it, through the leads 289, 291 and 292 to the power line 275. This is the normal operation of the stop gate circuit.

The solenoid 28 and relay 43 remain energized even though the switches 82 and 283 may have been opened in the meantime, until a stack of cartons opens the switch 42 mechanically, thereby opening the circuit. Opening the circuit tie-energizes the solenoid 2 8 so that the spring 27 pulls up the stop gate 22, and it de-eneergizes the relay 43 so that the switch 282 moves to normal position, closed against the lead 283.

The purpose of the manual switch 284 is to provide a way of actuating the circuit without having to rely upon the switch 82. Thus, suppose that the main switch 271 were opened, with the elevator 60 raised ofi the switch 82. When the main switch 271 was again closed, the stop gate relay 43 would remain de-energized, because both switches 82 and 284 would be opened. It might not be practical to restore the elevator 60 to its lower position, because to do so might mean throwing the counter 79 ofi at least one count. Therefore, the switch 284 is closed to energize the stop gate relay 43 and the solenoid 28 in exactly the same manner as closure of the switch 82.

(B) The circuitry of the motor 36 and some related parts A lead 293 from the power line 276 is connected by a lead 294 to the switch 83 and through it, to a lead 295 which is connected to one side of the elevator lift switch 64. When the switch 64 is in its normal position, shown in FIG. 13, it rests against a contact 296 which is connected by a lead 297 to a normally closed manual switch 298, provided for emergency use. The manual switch 298 is connected, via lead 299, to the relay 265 controlling the motor 36, the opposite side of the relay 296 being connected through the lead 300 to the power line 275.

Thus, with the switches 83, 64 and 298 closed, the motor 36 will drive the belts 30, 31, and opening of any of these switches stops the motor 36 and its belts. It will be recalled that entry of the stack A into the stacker D against the stops 39 does open the switch 64 during the initial raising of the elevator 60, and that movement of the cam 100 of the ejector F opens the switch 83.

(C) The elevator control circuit When the stock A enters the stacker D and engages the stop 39, it throws the switch 64 away from the contact 296 (thereby stopping the motor 36) and against a contact 301. The contact 301 is connected by a lead 302 to a contact 303 normally closed by a relay-controlled switch arm 304. The normally open contact 305 of the relaycontrolled switch 304 is connected by a lead 306 directly to the lead 295. The movable switch arm 304 is at all times connected by a lead 307 to the normally-closed elevator-return switch 68. A lead 308 connects the switch 68 to a lead 309, which goes to one side of the relay 65 and to a lead 310 which goes to one side of the solenoid 66, which operates the valve 66a that lifts the elevator 60. The other side of the solenoid 66 is connected by a lead 311 to the leads 291, 292, and the other side of the relay 65 is connected by a line 313 to the lead 291, which is connected through the lead 292 to the main power line 275.

Thus, when the switch 64 is thrown against the contact 301, current passes from power line 276 through leads 293 and 294, switch 83, lead 295, switch 64, contact 301, lead 302, contact 303, switch 304. lead 307, switch 68, leads 308 and 309, to the relay 65 and from there through leads 313, 291 and 292 to the power line 275, energeriz ing the relay 65. Simultaneously, the solenoid 66 is energized by the parallel circuit through leads 310 and 311. The holding relay 65 immediately takes over and 12 closes the relay switch 304 against the contact 305, so that the power thence comes directly from the line 295 through lead 306 and switch 304 to the switch 68 and thcrethrough to retain the relay 65 and solenoid 66 energized. Then, when the switch 64 returns to its normal contact 296 and opens the contact 301, by virtue of the elevator 60 having raised the stack A above the switch 64, the elevator 60 continues to rise. The elevator 60 is stopped when one switch 68 is opened either by the elevator reaching a desired height or by the return of the gates 50 and 51. When this happens, the relay 65 and solenoid 66 are de-energized, and the switch 304 returns to the contact 303 which is, of course, then an open circuit. The porting of the solenoids valve 660 is reversed;

r so the elevator 60 drops to its lowered position and, as

stated earlier, energizes the switch 82 at that lower position.

(D) The ejector circuit The lead which is connected between the power line 276 and the lead 291, is also connected to a lead 320or the lead 320 may be connected directly to the line 276, if desired. One branch, 321, from the lead 320, passes to one side of the ejector operating relay 84, which is normally open. The other branch lead 322 is connected by a lead 323 to the main ejector solenoid 85 and by a lead 324 to the return-air solenoid 105 for returning the ejector F. The circuit to the return-air solenoid 105 is normally open because the other side of the solenoid 105 is connected by a lead 325, to one side of the normally open switch 104, which does not close until the cam is moved by movement of the ejector piston 89.

The other side of the ejector solenoid 85 is connected by a lead 326 to a normally closed interlock-switch 327 located in the accumulator G and adapted to be opened whenever the belts 91 are lowered, so that the ejector F cannot push the stack E into the accumulator G if the belts 91 are not in their raised position. The other side of the switch 327 is connected by a lead 328 to the normally closed switch 69 which is actuated by the gate 51 to prevent motion of the ejector F in case both gates 50 and 51 are not closed.

The opposite side of the switch 69 is connected by a lead 330 through a normally closed switch 331 in the accumulator motor relay 266 to a lead 332. When the relay 266 is energized, the switch 331 is opened, so the ejector F cannot run while the motor 123 is running.

The lead 332 is connected by a lead 333 to a normally open contact 334 of the relay 84. It is also connected by a lead 335 to the normally open counter-actuated switch 81. The lead 332 is also connected in series to a lead 336, the normally closed first-stroke ejector-return switch 103, a lead 337, the normally closed second-stroke ejectorreturn switch 108, a lead 340 and the relay 84, on the side opposite the lead 321. In parallel with the switch 103 and across leads 336 and 337 is the normally open second-stroke by-pass switch 107. A normally open relay-controlled switch 341 is also normally closed against contact 342, which is connected by lead 343 to the normally open switch 104. The other side of the switch 341 is connected to both the switch 81, by a lead 344, and to the leads 293 and 294 by a lead 345.

Upon closure of the switch 81, current passes from the power line 275, by leads 292, 291, 320, and 321, to the relay 84, and from there via lead 340, switch 108, lead 337, switch 103, leads 336 and 335, switch 81, and leads 344, 345 and 293 to the other power line 276. The current, therefore, energizes the relay 84, moving the switch arm 341 away from the contact 342 and against the contact 334. Now current flows from power line 275 through leads 292, 291, 320 and 321 to the relay 84 and thence through leads 340, switch 108, lead 337, switch 103, leads 336, 335, and 333, contact 334, switch 341, and leads 345 and 293 to the power line 276. The

13 relay 84 is thus held energized, and it continues to hold the switch 341 against the contact 334.

With the relay 84 energized, the current passes from the line 275, via leads 292, 291, 320, 322 and 3123, through the pusher solenoid 85, lead 326, switch 327, lead 328, switch '69, lead 330, switch 331, leads 332 and 333, contact 334, switch 341 and leads 345 and 293 to the power line 276. Therefore, the solenoid 85 is energized and its valve 85a causes the ejector F to move.

Movement of the ejector F immediately moves the cam 100 and opens the switch 83, stopping the motor 36. Simultaneously, the movement of the cam 100 causes the switch 104 to close, but nothing happens from this just yet, because the switch 104 is connected to the open contact 342.

As the cam 100 is moved by the ejector F in its first stroke, it opens the switch 103. This, of course, opens the circuit and de-energizes the relay 84, returning the switch 341 to its normal position against the contact 342. Therefore, the solenoid 85 is de-energized and the ejector F is stopped. But, the switch 104 is now closed; so current flows from the power line 275, via leads 292, 291, 320, 322 and 324, to the return-air solenoid 105 and from there through lead 325, switch 104, lead 343, contact 342, switch 341 and leads 345 and 293 to the power line 276, thereby energizing the solenoid 105, whose valve 105a causes the ejector F to be pushed back to its normal position. The solenoid 105 is (lo-energized when the cam 100 breaks the switch 104 and simultaneously closes the switch 83, starting the motor 36.

With one package E already in the accumulator G, the operation of the second stroke of the ejector F difiers only in that the cam 100 continues to move past the opened switch 103, because the first package E shortly after beginning its movement-closed the by-pass switch 107, causing the current to by-pass the switch 103 through the switch 107. The ejector F therefore continues to move until the cam 100 opens the switch 108, upon which the return circuit is again brought into play, exactly' the same way as before.

(E) Circuit for lifting and lowering the belts 91 FIG. 8 shows the solenoid 118, relay 119 and switch 120 so actuated that the belts 91 are in their lower position. At this point, the solenoid 118 is connected to the power line 275 via leads 350 and 351, and on its opposite side is connected to a lead 352, one branch 353 of which leads through the normally closed switch 120 and lead 354 to one side of the relay 119. However, the other side of the relay 119 is simply through a lead 355 back to lead 350, so there is no circuit then and the relay 119 is not energized by that circuit. Another branch 356 from lead 352 goes to the relay-controlled switch 357 which, at this time, rests against contact 358, which by lead 360 is connected through a closed portion 361 of the switch 125and a lead 362 to a lead 363. The lead 363, in one direction, goes down to the normally open relay 127 and, in its other direction, to the normally open interlock-switch 128.

The connection to the power line 27 6 is through a lead 364, one branch 365 of which passes to the normally open contact 366 of the switch 357. The other branch 367 passes to the open portion 368 of the switch 125. The other side of the switch portion 368 is connected by a lead 369 to the switch 357. The switch 125 is manually operated, and until it is closed the belts 91 remain in their lower position, as they are when the current is 011, due to the fact that the air cylinder 116 is bled when the solenoid 118 is not enengized.

Operation, therefore, begins by moving the switch 125 manually to the position where its switch arm 368 closes across leads 367 and 369. At the same time, it will be .noted that the switch 361 is opened. Current from the power line 276 flows via leads 364 and 367, switch portion 368, lead 369, and lead 352, to the solenoid 118, from which, by leads 351 and 350 it flows to the other side of the line 275. Therefore, the solenoid 118 is immediately energized, and its valve 118a starts raising the belts '91. At the'same time, the parallel circuit from lead 356 passes via lead 353, switch 120, and lead 354, to the relay 119 and from the other side of the relay through leads 355 and 350 to the power line 275, energizing the relay 119. This moves the switch 357 away from the contact 358 and against the contact 366. This, in turn, means that now current flows directly to the solenoid from the line 276 via leads 364 and 365, switch 357, leads 356 and 352 and, through the solenoid 118, through the leads 351 and 350, to the line 275. This current continues to energize the solenoid 118 after release of the switch 125, which returns to its normal position. Current also fiows via theswitch 120, directly through the relay 119, and holds it energized. This means that the belts 91 stay up until switch 120 is opened, either manually (if that should be desired) or, in normal operation, by arrival of the stack E at the end of the accumulator G, depressing the switch 120. When the switch 120 is opened, the solenoid 118 and relay 119 are de-energized, the switch 357 moving back against the contact 358. The de-energization of switch 119' and solenoid 118, of course, causes the belts 91 to be lowered for insertion of the cap sheet. After the cap sheet has been inserted and it is desired to start operations again, the belts 91 are raised by manually pressing the switch and holding it momentarily until the relay 119 takes over.

(F) Circuit for moving the stacks E and E from the accumulator G to the press The motor 123 which drives the belts 91 and 92 is energized by the relay 266, one side of which is connected to the power line 275 through a lead 370. The other side is connected via lead 371 to the switch 128. The switch 128 is open when the belt 91 is lowered and is closed when the belt 91 is raised, by mechanical engagement of the belt frame 110. The switch 128 is connected to a normally open contact 372 adjacent the relay 127 by the lead 363. Moreover, since the switch 128 is open as long as the belt 91 is down, actuation of the relay 119 has no effect on the motor 123.

The relay 127, when energized, closes two normally open switches; closing switch 373 against the contact 372 and the switch 374 against a contact 375. The

switches 373 and 374 are always connected together by lead 376 and are connected through lead 377 to one side of the relay 127. They are also connected via lead 378 to a contact at a normally open switch 126. The normally open contact 375 of the switch 374 is connected via lead 381 to a pole 382-on the opposite side of the manual switch 126. The lead 381 is also connected throughpole 385 to the normally closed manual stop switch 386,'which can be used to stop the motion of the motor 123 at any time, as will be seen hereafter.

The opposite side of the relay 127 is connected by leads 390 and 391 to the power line 275. The other side of the switch 386 is connected by a lead 392 to the normally closed switch 151 at the stop gate 150. The other side of the switch 151 is connected by lead 393 to the power line 276.

It will be obvious from the drawings that the circuit, as shown, is open'because switches 126, 373 and 374 are all open. For operation of the circuit, therefore, the manual switch 126 is closed for a moment and bridges between lead 378 and pole 382. The current can flow from line 276 via lead 393, switch 151, lead 392, switch 386, pole 385, lead 381, pole 382, switch 126, leads 378, 376 and 3 77, relay 12 7 and leads 390 and 391 to the power line 275. As a result, the relay 127 is enengized and switches 373 and 374 are closed. Current can then flow from the power line 276 via lead 393,

switch 151, lead 392, switch 386, pole 385, lead 381, contact 375, switch 374, lead 376, switch 373, contact 372, lead 363, switch 128 (if the belt is up), lead 371, relay 266 and lead 370 to the line 275. The resultant energization of the relay 266 starts the motor 123 and drives the belts 91 and 92. Similarly, the current from the line 276, flowing as before to the lead 376, also flows through lead 377, relay 127, and leads 390 and 391 to the line 275, keeping the relay 127 energized after the switch 126 is released.

The motor 123 can, of course, also be stopped by manually opening the switch 386.

OPERATION The operator starts the device by closing the master control switch 271 which energizes the master-control relay 270. With the device in its normal position, this will cause the belt-drive motor 36 to operate, moving the belts 30, 31. Small stacks A of boxes B enter the machine from the conveyor C, one at a time. As the first stack A enters and comes into the belts 30, 31, it is pulled away from the stacks A behind it by the greater speed provided by the driving belts 30 and 31 as compared with the gravity feed of the rollers 21. This causes the first stack A to have a gap between it and the second stack, so that when the stack A opens the switch 42, the solenoid 28 is deenergized. The weight of the boxes in the first stack A is sufiicient to hold the gate 22 down until it has passed be yond it, but upon its having passed, the gate 22 is immediately pulled up by the spring 27. The gate 22 then stops the next stack A until the switch 82 is later energized (or the manual switch 284 is closed). This normally happens only after the stack elevator 60 has lifted the first stack A above the gates 50, 51 and has returned to its bottom position.

The first stack A, moving along the belts 30, 31, passes between the straightening guides 33 into the stacker frame and comes against the stop 39, moving the switch 64 from contact 296 to contact 301. This stops the motor 36 until the boxes B are lifted above the switch 64, and it energizes the relay 65 so that the solenoid valve 66a sends air into the pneumatic cylinder 61 to raise the elevator 60 with the stack A on top of it. As the raising continues, the stack A pushes open and upward the gates 50, 51. After the stack A passes above the top of the gates 50, 51, the springs 54 close the gates 50, 51 below the stack A, and closing of the gate 50 (or attainment by the elevator 60 of a predetermined height) opens the switch 68, de-energizing the relay 65 and the solenoid 66, so that the valve 66a sends airs into the opposite end of the cylinder 61 and lowers the elevator 60. As the elevator 60 goes down it leaves the first stack A on top of the gates 50 and 51.

When the elevator 60 returns, it energizes the switch 82 opening the gate 22 and sending the second stack A into the stacker D. The switch 64 is again energized, and the elevator 60 carries the second stack A above the gates 50, 51 and adds it beneath the first stack A. The elevator 60 again drops, and continues in this manner to lift stacks A above the gates 50, 51 until the required number necessary to make the stack E has been reached. By way of example we have given the number of seven stacks A to be incorporated into the stack E; and so a seven-toothed ratchet wheel 79 is provided.

The return of the elevator 60 in each instance causes the dog 76 to move against a ratchet tooth 78 and move the ratchet wheel 79 around one tooth. At the seventh tooth, the projection 80 closes the microswitch 81, energizing the relay 84. This energizes the solenoid 85, and its valve 85a sends the ejector F forward. The pusher block 90 at the forward end of the piston 89 moves the stack E forward, forcing open the gates 40, 41 against the pressure of the torque springs 46. After the pusher 90 has pushed the stack E forward, beyond the gates 40, 41, the springs 46 close the gates 40, 41 and, shortly there- 16 after, the switch 103 is opened by the cam 100 on the cam rod 101. This de-energizes the relay 84 and deenergizes the solenoid 85. It also energizes the return air solenoid 105, and its valve 105a sends air into the opposite end of the cylinder 87 at the port 106 and retracts the pusher block 90.

When the ram began its pushing action, the interlock switch 33 opened; so the motor 36 stopped and it became impossible during operation of the ejector F to deliver any more stacks A into the stacker D. Upon the return of the ejector F, the switch 83 is closed by the cam so that the motor 36 again begins running, and a new series of stacks A is taken into the stacker D and formed into the stack E, as before.

The second stack E having been formed, it is pushed, as before, by the ejector F on actuation by the seventh ratchet tooth. As before, the belts 91, 92 aid the ejector F in this pushing. After the ejector F and second package E begin pushing the first package E the package E, engages and closes the switch 107 which by-passes the switch 103, so that when the cam 100 opens the switch 103 nothing happens, and the pusher 90 continues to move until the second-stop switch 108 is opened by the cam 100. Then, as before, the relay 84 and solenoid 85 are de-energized and the solenoid is energized, retracting the ejector F. Also as before, the motor 36 is stopped during movement of the ejector F and, as before, the motor 36 begins to run again as soon as the cam 100 engages the switch 83 and closes it.

At the end of its stroke, the forward bundle E in the accumulator G opens the switch 120, which de-energizes the relay 119 and the solenoid 118, bleeding air from the cylinder 116 and lowering the frame that carries the belts 91. The stacks E and E are thereby lowered to rest on the wings 111. A cap sheet H is inserted between the belts 9'1 and wings 111, if desired at this time, depending upon whether this is the first group of two packs E and E 'or the second group of two packs to go through the accumulator G. After the cap sheet H has been put in manually and, if other things ahead are clear, the operator presses the manual switch 126 which energizes the relay 127 and starts the motor 123.

The motor 123 causes the belts 91, 92 to move the stacks E and E to the press. During the movement from the accumulator G, the folders 131 force in the projecting edges of the cap sheet H, and the rollers 132 press the edge portions 130 straight against the side of the package.

To those skilled in the art to which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

What is claimed is:

1. In a machine for packaging k.d.f. corrugated cartons, a stacking device comprising: a set of powerdriven conveyor belts for moving small stacks of k.d.f. cartons; a pivotally mounted stop gate adjacent the intake end of said conveyor belts, spring urged to prevent entry therein of stacks; a solenoid which, when energized, retracts said stop gate to permit entry of a small stack of cartons on to said belts; a switch located less than a carton length beyond said stop gate and tripped by engagement with a passing small stack for deenergizing said solenoid and closing said gate; stationary stop means adjacent the other end of said belts for stopping the forward progress of said small stacks of cartons; an elevator for raising said small stack up off said belts; actuator means at said stationary stop means engaged by said small stack of cartons striking said stop means for actuating said elevator; normally horizontal swinging gates through which said elevator lifts said small stack, said swinging gates closing automatically after said small stack. has passed beyond them; means to retract said elevator and deposit said small stack on said swinging gates; switch means for energizing said solenoid for opening said stop gate when said elevator drops below the level of said belts, to admit another small stack of cartons that passes through the same cycle, being added to the bottom of the previous small stack above the gates; counter means for determining a specified number of small stacks of cartons to be serially added in the aforesaid manner to the bottom of the first small stack over said swinging gates to constitute a first large stack of k.d.f. cartons; means actuated by said counter for automatically ejecting said first large stack horizontally; conveyor means over which the ejected stack is moved; first return means for returning said ejecting means, when said first large stack reaches a predetermined location; a second large stack then being formed and ejected and moved against said first large stack and over said conveyor means; means for de-activating said first return means during ejection of said second large stack; second return means for returning said ejecting means after said large stacks have been moved to a predetermined location along said second belts; means for lowering said second belts when said second return means has been actuated; means for supporting said large stacks when said second belts are lowered, so that an oversize lower locking sheet can be inserted beneath the bottom of both said stacks and above said second belts; and means for raising said second belts and for driving them by power so as to advance both said large stacks and said lower locking sheet together.

2. In a machine for packaging k.d. f. corrugated cartons, a stacking and accumulating device comprising: means for stacking a series of small stacks of cartons into a larger stack; counter means for counting the number of small stacks added together to constitute a first large stack of k.d.f. cartons; means actuated by said counter for automatically ejecting said first large stack horizontally when a specified number of small stacks have been stacked; conveyor means over which the ejected stack is moved; first return means for returning said ejecting means when said first large stack reaches a predetermined location along said conveyor means, a second large stack of the same number of small stacks then being formed and ejected and moved against said first large stack and over said conveyor means; means for de-activating said first return means during ejection of said second large stack; second return means for returning said ejecting means after the two said large stacks have been moved to a predetermined location on said conveyor means; means for lowering said conveyor means when said second return means has been actuated; means for supporting said large stacks when said conveyor means are lowered, so that an oversize lower cap sheet can be inserted beneath the bottom of both said stacks and above said conveyor means; and means for raising said conveyor means and for driving it by power so as to advance both said large stacks and said lower cap sheet together.

3. In a machine for packaging k.d.f. cartons that have been stacked, the combination of: conveyor means on which two stacks are moved; means for retracting said conveyor means while holding said stacks up so that a single oversize lower cap sheet may be placed beneath the bottom of both said stacks; means for raising said conveyor means again so that they again support said stacks; means for advancing both said stacks and said lower cap sheet together while folding marginal portions of said lower cap sheet upwardly, against marginal portions of the ends common to both said stacks; and a press, to which said stacks are advanced and baled.

4. A device for accumulating pairs of stacks of k.d.f. cartons, inserting a single cap sheet beneath a said pair of stacks, and for conveying the resultant group to a press, comprising: a main frame; a conveyor frame movable up and down relative to said main frame; conveyor means supported by said conveyor frame for receiving said stacks; means for lowering said conveyor frame when two said stacks have been accumulated; means on said main frame for supporting said large stacks when said conveyor means are lowered, so that an oversize lower cap sheet can be inserted beneath the bottom of both said stacks and above said conveyor means; and means for raising said conveyor means and for driving it by power so as to advance both said large stacks and said lower cap sheet together.

5. The device of claim 4 having means for folding marginal projecting portions of said lower cap sheet upwardly, against marginal portions of the sides common to both said stacks, as said advance takes place.

6. A device for accumulating pairs of stacks of k.d.f. cartons, inserting a single cap sheet beneath a said pair of stacks, and for conveying the resultant group to a press, comprising: a main frame; a conveyor frame movable up and down relative to said main frame; a pair of conveyor belts supported by said conveyor frame; means for lowering said conveyor frame and its belts when two said stacks have'been accumulated; marginal flanges on said main frame for supporting said large stacks when said belts are lowered, so that an oversize lower cap sheet can be inserted beneath the bottom of both said stacks and above said belts; means for raising said belts and for driving them by power so as to advance both said large stacks and said lower cap sheet together;

and means for folding marginal projecting portions of said lower cap sheet upwardly, against marginal portions of the ends common to both said stacks, as the advance takes place.

References Cited in the file of this patent UNITED STATES PATENTS 1,505,595 Hilsinger Aug. 19, 1924 2,647,645 Pierce Aug. 4, 1953 2,769,570 Adams Nov. 6, 1956 2,792,950 Fenton et al May 21, 1957 2,885,097 Lyon May 5, 1959 2,941,339 Salwasser June 21, 1960 

